The FTSE 100 has extended earlier gains and is now ahead 1.1% at 7,209.87.
In Germany, the DAX is up 1% and in France, the CAC-40 index has climbed 1.4% higher.
Investors are looking ahead to the minutes from the US Federal Reserve July meeting - released later - for clues about where interest rates are heading. Fed chairman Jerome Powell will also be giving a speech on Friday at the US central bank's Jackson Hole symposium.
People are looking ahead to Jackson Hole later this week and the message that Jerome Powell may or may not give us on the direction of monetary policy. That is the highlight of the week and we are waiting with bated breath."